Por and para are both prepositions, which means that they must
be followed by a prepositional object (a noun, pronoun or infinitive). Both
can sometimes mean for in English, but they can also be translated
in many other ways depending on the context, because they mean different
things. Para tends to focus on a destination of some
type. Por focuses more on the means to an end or the intervening
step or duration. Here are some samples of their uses: